液-液微萃取分光光度法测定钢铁及合金中钒

Determination of vanadium in steel and alloy by liquid-liquid microextraction spectrophotometry

结合自行设计的50μL液滴吸光度测定的分光光度计,建立了液-液微萃取分光光度法测定钢铁及合金中钒的分析方法。当萃取剂(三氯甲烷)用量为0.50mL,萃取时间为60s,钽试剂三氯甲烷的浓度为2.0g/L,测定效果最佳。实验表明,钒在0.025~0.5μg/mL范围内与其对应的吸光度呈良好的线性关系,线性方程为A=4.135ρ,线性相关系数r=0.999,方法检出限为0.002μg/mL。方法应用于钢铁及合金标准物质中钒的测定,结果与认定值相同,相对标准偏差(RSD,n=5)为1.5%~4.1%。

A liquid-liquid microextraction spectrophotometric determination of vanadium in steel and alloy was established with a self-designed 50μL-droplet-absorbance spectrophotometer.Optimal determination results were obtained with 0.50 mL of extraction agent(trichloromethane)and 2.0g/L tantalum reagent trichloromethane solution at an extraction time of 60 s.It was found that,vanadium showed a fine linear relationship with its absorbance within the range of 0.025-0.5μg/mL.The linear equation was A=4.135ρwith correlation coefficient r=0.999.The detection limit was 0.002μg/mL.This method has been used to determine vanadium in steel and alloy certified reference materials,whose results were consistent with the certified values.The relative standard deviation(RSD,n=5)was 1.5%-4.1%.